Lena will be pushed to her limits in the upcoming episode of "The Fosters" season 4.

In the previous episode titled "Forty," the family organized a 70's-themed party for Lena. However, the merrymaking turned into a mess when her mother turned up and her concerns about Stuart were brought up.

Elsewhere in the episode, Callie and Aaron went to prove that Kyle was innocent, while Mariana showed off her skills during a school competition. As for Jude, he was disappointed to know that Cameron came to town without his knowledge. The episode also saw Brandon go overboard just to earn extra bucks.

Titled "Justify," the upcoming episode will see how Lena will react to all the bad news coming her way.

The official synopsis for the episode reads, "Lena is shocked after finding out a secret her father has been hiding. As it turns out, the secret directly puts all of them in danger and she is worried about her family's safety. Lena will also discover a huge secret about Brandon which only makes matters worse."

Meanwhile, Nick will pressure Mariana after she decided to cut ties with him. The episode will also follow Mariana as she tries to keep her cool while working with the male members of the STEAM team, whose ideas run in conflict with hers. Jesus will also begin to bear a grudge on Emma's attitude.

In the promo trailer for the episode, the voiceover says, "Every move, every mistake and every secret will come out." The video shows Mariana's foster brother finding out that she has been visiting Nick in secret. The last part of the trailer shows Brandon and Lena having a heated confrontation about the money that Brandon gave to Cortney.

"The Fosters" season 4 airs every Monday, 8:00 P.M. on Freeform.